Filter impregnating machine



A g: 22 1939. F. B. HALE Er AL 2,110,1 2

F ILTER IMPREGNATING MACHINE Filed June 28, 1932 8 Sheets-Sheet 1INVENTORSI 27am? 5. Hale BY Hum/b11470 f1 ATTORNEY.

Aug. 22, 1939. F B HALE Er AL 2,170,142

FILTER IMPREGNATING MACHINE Filed June 28, 19732 8 Sheets-Sheet 2 IN VENTOR-5 A TTORNE Y.

Aug. 22, 1939. F B HALE E1- AL 2,170,142

FILTER IMPREGNATING MACHINE Filed June 28, 1952 s SheetsSheet 3 yEran/n41 Loyd/2 A TTORNEY.

Fv B. HALE El" AL 2,170,142

FILTER IMPREGNATING MACHINE Filed June 28, 1932 8 Sheets-Sheet 4 Aug.22, 1939.

Aug. 22, 1939. F. B. HALE ET! AL 2,170,142

FILTER IMPREGNATING MACHINE Filed June 28, 1952 s Sheets-Sheet 5INVENTORS Pia/7A .5 Hale y 401 A TTORNE Y.

Aug. 22, 1939. F, B. HALE ET AL FILTER IMPREGNATING MACHINE 8Sheets-Sheet 6 Filed June 28, 1932 Aug. 22, 1939. L -r AL 2,170,142

FILTER IMPREGNATING MACHINE Filed June 28, 1932 I 8 Sheets Cheet 7 ATTORNE Y.

Aug. 22, F B HALE ET AL FILTER IMPREGNATING MACHINE Filed June 28, 19328 Sheets-Sheet 8 INVENTORS flan/ B f/aZe By Fhw/zALa owz A TTORNE Y.

Patented Aug. 22, 1939 UNITED i STAT-ES PATENT OFFICE arasota, Fla

Application June 28, 1932, Serial No. 619,730

50 Claims.

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) The invention described hereinmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to us of any royalty thereon.

The invention relates to filters for gases, vapors and smokes and moreparticularly has refierence to a machine'for impregnating such filterswith finely divided or pulverized material.

It has been found that the efficiency of a 10 as filter is increased bythe clogging of the pores of the filter material by a finely dividedsubstance.

entire surfaces thereof with the impregnant as ll well as impregnatingseveral filters, either separately or simultaneously, to a like degree.Another disadvantage in devices for this purpose resides in the factthat their operation is not continuous, it being necessary to completelyar- 20 rest their operation while loadingthe same with filters to beimpregnated and while removing impregnated filters therefrom.

It will hence be apparent that the major object of our invention is theprovision of a machine of simple design and easy operation for theimpregnation of filters with a finely divided material.

' An equally important object of our invention is the provision of a,machine for impregnating 80 a plurality of filters with finely dividedmaterial, each being impregnated to an equal degree. Another object ofour invention is to devise a filter impregnating machine of suchcharacter that one set of filters may be loaded or removed T as from themachine while another set of filters are undergoing impregnation, thusaffording a continuous operation of the device.

Still another object of the invention is the provision of an automaticfeeding device for the 40 impregnating material which determines thequantity of the material employed in each impregnation.

Yet another object of our invention is to provide a means forautomatically regulating the 45 degree of impregnation of the filtersundergoing treatment in a filter impregnating machine, by means of anovel automatic timing device.

Still another object of our invention is to devise a filter impregnatingmachine having means 50 associated therewithior brushing the excess ofmaterial used in impregnation off the surface of the filters undergoingtreatment. v A further object of our invention is the provision of animpregnating machine including two impregnating compartments in whichthe filters I-Ieretofore, difflculties encountered in impregnatingfilters have been in treating the k excess impregnating material fromthe impregundergoing treatment are rotatably mounted, a hoppercontaining the impregnating material being associated with the device soas to communicate with either chamber and means provided on the machinefor passing a current of air 5 through a chamber in the hopper andimpregnating either compartment.

A still further object'of the invention is to provide means'for removingfrom the impregnation compartment of an impregnating machine, the excessimpregnating material therein.

Yet a further object of our invention is the provision of means in afilter impregnating machine for connecting the unimpregnated filters toa vacuum pump while the filters are being rotated in an air streamcarrying particles of impregnant.

With these and other objects in view, which may be incident to ourimprovements, the invention consists in the parts and combination to behereinafter set forth and claimed, with the understanding that theseveral necessary elements comprising our invention may be varied inconstruction, proportions and arrangement without departing from thespirit and scope of the appended claims.

One manner of practically effecting the concept of our invention is tomount upon a. suitable supporting frame, an impregnating box dividedinto compartments or chambers, each of these compartments having hollowrotatable shafts therein on which are mounted the filter material.Associated with the impregnating box and adapted to form a closure foreach of the impregnating compartments, when the filter material thereinis undergoing treatment, is an airtight top or cover which is connectedthrough a flexible conduit to a hopper containing the impregnatingmaterial and to a source of air under pressure.

For evacuating air from within filters being treated, each of theirhollow mounting shafts leads to a manifold which is connected to avacvuum pump. One manifold is provided for each impregnating chamber sothat through suitable control valves only one chamber at a time isconnected to the vacuum pump. As well as the exhausting apparatus, justmentioned, a suction blower is employed for the purpose'of removingnating chambers. 1

Our invention also comprehends the rotation of the filters undergoingtreatment, a brushing mechanism for each filter, a'timing mechanism anda feeding device from a main power source. I g

By means of these last two units, which control the quantity ofimpregnating material employed and the time of impregnation, the degreeof impregnation of the filters is determined.

In order to make our invention more clearly understood, we have shown inthe accompanying drawings, means for carrying the same into practicaleffect without limiting the improvements in their useful applications tothe particular constructions, which for the purpose of explanation, havebeen made the subject of illustration.

In the drawings:

Figure 1 is a side view, partly in section, of the machine forming thesubject matter of our invention.

Figure 2 is a top plan view, partly in section, of the machine disclosedin Figure 1.

Figure 3 is an end elevation of the impregnating machine.

Figure 4 is a longitudinal sectional view showing in detail the feedingunit employed with the impregnating machine.

Figure 5 is a part transfer sectional and part rear view, showing indetail the impregnation box of the device.

Figure 6 is a longitudinal sectional view of the timing mechanism.

Figure 7 is a detail top plan view of the timing mechanism.

Figure 8 is a sectional view of the timing mechanism taken along theline 8-8 shown in Figure 6.

Throughout the drawings similar reference numerals refer to like partsin the different views.

, In Figures 1 through 3, We have shown a machine of the naturedescribed which comprises-a suitable supporting frame or bed, generallydesignated by the reference numeral 9. This frame, which is ofrectangular shape, may be formed of structural steel members and isprovided with a base and a top, the latter including the side members 2and end members 3.

On the top of the frame or bed of the machine there is mounted animpregnating box a which is divided into compartments or chambers 5 and8 by a partition 1 extending the full length of the box. Theunimpregnated filters 8 which may be of any shape are placed within animpregnating compartment. Hollow threaded members 3 associated with eachfilter engage internally threaded hollow shafts ill, to thus support thefilters, and to provide an air-tight connection with shafts l0. Theseshafts H) which extend through the side walls ll of the impregnating box4 are mounted for rotation in bear ings 12 associated with the boxwalls. -It may be noted that each shaft supports a piece of filtermaterial.

Also mounted within each impregnating compartment are rotatable shaftsl3, there being such a shaft provided for each piece of filter materialsupported for rotation on the shafts Ill. The shafts I3 have their endsextending through the side walls H of the impregnating box and aresupported in bearings l4 and I5 provided on the walls H and thepartition 1 of the box 4. Secured to each shaft l3, in any suitablemanner, is a brush element l6 which, is adapted to sweep excessimpregnating material from the surface of a piece of filter material 8on the oscillation of the shaft.

vassociated. Each of these arms is pivoted to a chine chassis. Eachshaft I1 and I8 has a sprocket wheel secured thereto while each filtersupport shaft ID has a sprocket 2| keyed or otherwise fastened theretoat a point on the shaft outside the impregnation box wall. sprockets 2|for the compartment 5 and the sprocket on the shaft [l are engaged byone of a pair of endless chains 22 while the other chain 22 connects thesprockets 2| of the compartment 6 to the sprocket on the shaft l8 Thusit will be apparent that either set of filter material support shaftsmay be rotated depending upon which of the driven shafts, I! or I8, isactuated.

To the end that the brush members or elements it may be oscillated uponthe rotation of the filter material, each of the driven shafts l1 and itare provided with an eccentric 25 which may, as disclosed, be formedintegral with a sprocket 2t. Connected to each eccentric 25 is a maindrive link 26 to which a side drive link 21 is pivotally secured, in anysuitable manner, at the point 28. Each side link 21 is provided with aplurality of arms 29, one for each brush shaft I3 of the compartmentwith which the link is link 21, in any well known manner, at points 30and have their lower ends connected to brush carrying shafts l3 asclearly shown in Figure 5. By this construction it will be apparent thatrotation of an eccentric, to which a main and side link are connected,will cause the oscillation of the brush shafts engaged by the arms ofthe side link. Moreover, it may be observed that through the use of twodriven shafts simultaneous actuation of the filter support shafts andthe brush carrying shafts in either compartment is allowed.

Power for the actuation of the filter support and the brush carryingshafts as well as for the operation of a timing mechanism and feedingdevice for the impregnating material, the latter to be hereinafterdescribed, is obtained from a main power source such as the electricmotor 3!. The motor 3! is connected by a belt 32 to a pulley 33 securedto the shaft 34, the latter being carried in bearings 35 supported onthe base of the chassis frame. In addition to the pulley 33, there isalso secured to the shaft 34 a second pulley 36 which latter, by belting31 is connected to a pulley 39 or pulley 48 respectively keyed orotherwise secured to the shafts l1 and I8.

As may be noted, the pulleys 39 and 40 are positioned on the adjacentends of the shafts l1 and 58 so that the belt 31 may-be shifted from onepulley to the other for the purpose of allowing operation of the filtersupport shafts and brush 55 carrying shafts in either impregnatingcompartment. In order to accomplish this, a lever 4| carrying a shiftingfinger 42 is suitably pivoted to the frame of the machine so as to rocktransversely thereof. By reason of the movement of finger 42, the belt31 is engaged and shifted onto either the wheel 39 or 40 as desired.

Mounted upon a suitable standard or support 43 at the right end of themachine, as shown in Figure 1, is a hopper 44 in which the impregnat ingmaterial in a finely divided or pulverized condition, such as lamp blackfer example, is loaded. The hopper 44 is provided with shafts- 45 and 46supported therein by hearings in the side of the hopper, one end of eachshaft extending through 7 a side of the hopper. Each shaft 45 and 46 isprovided with paddles 41, which in their rotation agitate theimpregnating material within the hopper.

As may be noted, especially well in Figures 1 7 The and 4, the -lowerend of the hopper is provided with an atomizing chamber 48 Just abovewhich is mounted a shaft 48 one end of which also extends through thehopper. Shaft 48 carries a meter unit 58 provided with grooves 5|, thelength and diameter of the meter unit being such that the portion of thehopper above the meter is substantially closed off from the atomizingchamber 48. It will thus be appreciated that the hopper being loadedwith impregnating material, a groove in the meter unit will be filledwith this material and on rotation of the meter, the amount ofimpregnating material carried on the groove will be introduced into theatomizing chamber. Hence it will be apparent that on regulation of thenumber revolutions of the meter, a predetermined amount of lamp black orother impregnating material will be discharged into the atomizingchamber for impregnation purposes.

Connecting the right end of the chamber 48 with a source of air underpressure is a pipe or conduit 52 while the left end of the chamber isconnected to a flexible conduit 53. The supply of air entering thechamber 48 is controlled by a valve 54a having an elongated handle 59which extends lengthwise of the machine to the left end thereof. Thisvalve rod or handle is supported from the machine frame in anyconventional manner. When in operation, air flowing under pressurethrough the pipe 52 enters the chamber 48 and blows the lamp black fromthe grooves 5| of the meter mechanism which are in the chamber, as wellas any lamp black which may have been deposited with n the chamber, intothe flexible conduit 53.

As already pointed out, the impregnating box 4 is provided with twochambers 5 and 8, one or the other being employed for an impregnation.To accomplish this, the box 4 is provided with a close fitting air tighttop 54 of a width sufficient to cover a chamber. I'his cover is slidablymounted in the ends of the impregnating box by any suitable meansproviding air tight joints so that either chamber desired may be coveredand sealed from the atmosphere of the room or place where the machine isoperated. For the purpose of moving the cover it is provided withhandles or grips 55. Cover 54 is so constructed as to have a hollowinterior and hence provide a manifold 58 of a width and lengthsubstantially equal to obtained. By reason of slots 58, formed in thelower surface of the impregnating compartment, entrance into thecompartment covered is .effected. The slots 58, it should be observed,are positioned directly over the centers'of the filters 8 so that theair stream containing the lamp black strikes the surface of the filters,forcing the particles of lamp black into the pores of the filtermaterial.

It will also be noted that as each filter rotates there is only a slightclearance between it and the inner surface of the manifold in order thatthe air stream carrying the lamp black will impinge directly andforcibly upon the filter to force the lamp black into the pores thereof.

From the description of our invention as already given, it may beobserved that on actuation of the meter unit, lamp black or otherimpregnating material will be blown through the conduit into animpregnating compartment top and from thence into either impregnatingcompartment,

depending on which compartment is closed. Through the rotation of thefilter material, undergoing impregnation, a uniform distribution of theimpregnating material is obtained over the surface thereof and into thepores thereof while the oscillation of the brush carrying shaftsprevents the accumulation of excess impregnating material on eachfilter.

It is desirable to evacuate air from within the filters being treatedand it is for this purpose that the filter support shafts III are hollowso that communication with the interior of a compartment and a manifoldconnected to a vacuum pump may be obtained. Particularly well shown inFigures 2 and 5 are manifolds 59 and 88 secured to each side of theimpregnating box 4. By means of conduits 8|, each shaft I8 is placed incommunication with its corresponding manifold. To be noted is the factthat a close fit'between the end of each shaft I8 and a conduit 8| ismade. In addition to this, near the outer end of each shaft I8 a fiange82 is provided which rotates in a depression .in the inner surface ofthe manifold. If desired, packing may be placed around each shaft l0where it enters a manifold.

Manifolds 58 and are respectively connected by pipes or conduits 83 and84 to a pipe 85 in which is a three-way valve 88 actuated by a valvehandle or lever 81. Connecting valve 68 with a valve 88 which is closedand opened by the valve handle 88'.is a conduit 89. Valve 88, throughmeans of a pipe 18, is in direct communication with a vacuum or suctionpump (not shown) of any suitable capacity and design. From the pipingsystem outlined, it may be observed that the amount of the exhaust maybe controlled by the valve 88 while the three-way valve 88 allows eitherimpregnating compartment to be exhausted, This piping system incombination with the hollow filter support shafts and the hollow clutchmembers, allows air to be sucked through and from within the filtermaterial being treated so as to increase the penetration of theparticles of impregnating material and hence the efiiciency of thefilter itself.

In addition to the vacuum pump system described, each impregnatingchamber is connected by means of a conduit ll, entering the chamberthrough an opening in its floor 54' (see Figure 5), to the intake of asuction blower 12 which is driven by an electric motor 13. Blower I2 isprovided with an exhaust line 14 leading to any desired location. Bythis expedient excess lamp black or other impregnating materialwhichsettles in the impregnating compartments is removed and saved forfurther use.

If desired, both impregnating compartments may be connected toa singleblower, or a separate blower can be employed for each'compartment. Theformer construction may be effected by providing the intake pipe of theblower with two branches. Suitable valves may be placed in each branchfor shutting off either compartment or a three-way valve at the Junctionof the branches may be used.

As already mentioned, the electric motor 3| is employed to actuate thefeeding mechanism within the hopper 44 as well as a timing device whichdetermines'the length of operation of the meter unit 58. For thispurpose, the shaft 34 isprovided with. a suitable pulley which isconnected by means of belting 15 to a pulley 18 carried on v a shaft 11supported from the under surface of the top of the machine frame. Theshaft 11 in addition has keyed thereto a bevel gear 18 which meshes withabevel gear 19 on one end of a shaft 89, the other end of the shaftbeing provided with a sliding clutch or coupling member BI. Coupling BIis adapted tobe engaged by a male coupling member 82 keyed or otherwisefixed to a shaft 83. As may be observed, shafts 89 and 83 are carried insuitable bearings 84 which are suspended from the top of the machineframe in any conventional manner.

Near its right end as viewed in Figure 1, shaft 93 is provided with twosprockets which are respectively connected by means of chains 85 and 86to a sprocket 81 carried on the paddle shaft 46 and a sprocket 88carried on the meter unit shaft 49. Besides the sprocket 81, shaft 46has keyed thereto a second sprocket 89 which is engaged to a sprocket99, carried on the paddle shaft 45 by the chain 9I. Through thisconstruction it will be observed that on engagement of the couplingmember 82 with the coupling member 8I and on actuation of the powersource 3I, rotation of the meter unit and the feeding device for theimpregnating material will be accomplished.

From the foregoing description, it will be ap-- preciated that theoperation of the moving parts of the machine are effected by reason ofthe prime mover of electric motor 3I. It is hence necessary to providemeans for starting the motor and for arresting its actuation. The motor3| through a suitable wiring system is connected to a switch 92supported from cross piece 95 of the chassis. This switch which is ofthe push button type, has the starting button thereof depressed bymovement of switch finger 93 pivoted at 99 on cross piece 95. Below thepivot, the switch finger is secured to a rod 96 which is slidablysupported, in any conventional manner, from the chassis top. Rod 96 isof a length sufficient to extend to the left end of the machine and overa bracket member or control mounting plate 91 secured to the left end ofthe machine.

This plate, as may be noted, at its side adjacent the machine frame, isprovided with a flange 98 so that one end of a spring. 99 carried on theleft end of the rod 96 will be in bearing relation therewith. At theleft end of the shaft 96 a suitable block or retaining member I99 issecured so that a construction allowing the spring 99 to be positionedbetween the flange 98 and the block is afforded. Thus it will beappreciated that on movement of the rod 96 to the right end of themachine which causes the finger 93 to contact with the switch button anddepress the same, will also compress the spring 99 between the flange 98and the block I99, the spring-being loosely mounted on the rod 96. Uponrelease of the rod 96, after it has been moved to the right, the energyof the spring 99 will cause it to return to the left or the positionshown in Figure 7.

Movement of the rod 96, in a manner such as that just described, iseffected by a lever I9I pivoted at I92 to a-bracket or standard I93carried on the top of the machine. As may be noted from Figure 7, thelower endof the lever I9I is secured or fastened to the switch rod 96 byany means, such for example as a screw or pin.

To arrest the actuation of the feeding mechanism and meter unit afterpredetermined time of operation, as well as the actuation of the motor3I, a timer wheel or pulley I94 fixed on a rotatable timer shaft I95 isemployed. The shaft I95 which is threaded, as at I96, for part of itslength is positioned'at right angles to the shaft 83, being supported inbearings I91 secured to the top of the machine chassis. Driving of thetimer shaft is accomplished through the use of a belt I96 running overthe timer pulley anda pulley I99 on the shaft 11.

Associated with the timer wheel and forming a part of the timingmechanism is a rod II9 slidably and rotatably mounted within bearingsIII carried on the machine top. This shaft, as may be noted, is of asufficient length to extend from a point near the timer shaft I95 to theleft end of the machine so that the left end of the shaft extendsthrough and beyond the control mounting plate 91.; An arm H2 is securedto the end of the rod II9 adjacent the timer shaft. Timer arm H2 is heldin fixed relation to the timer rod so as to rotate therewith by anysuitable means, as for'examp-le the bolt II3 holding the arm in fixedposition against a block or enlarged portion IId on the timer controlrod.

At its lower end, arm II2 has fixed thereto by a cap screwi I5; a halfnut H6 which is adapted to be engaged by the threads on the timer shaftand hence to be moved on the rotation of the latter. Half nut I I6carries a finger I I1, which is employed to depress the stop button ofthe switch 92 so as to arrest the operation of the main power unit 3|.

To provide a guide for the half nut, it is mounted to slide on twosupport shafts II8, the end of each support shaft being mounted in aslidable carriage member or piston II9 which may be moved against theaction of a spring I29 in a cylinder I2I carried on a cross piece I22 ofthe chassis. Thus it will be appreciated that engagement ordisengagement of the half nut by movement of the timer control rod I I9lengthwise of its axis will be allowed while rotation of the time shaftI95 will cause the movement of the half nut while engaged therewith,which latter is guided by the tracks or slides II8.

Inasmuch as the timer control rod and its arm H2, are rotated when thehalf nut is engaged with the timer shaft, the opening I23 in the timerarm, through which cap screw II5 passes, is in the form of an elongatedslot. This construction expedient allows compensation for the linearmovement of the half nut and prevents binding of the parts of the timermechanism.

Longitudinal and rotative movement of the timer rod II9, for the purposeof setting the half nut at any desired position on the threads of thetime shaft is effected by means of a lever I24 pivoted 'at I25 to theend of the timer rod which extends through the control support bracket.This lever is provided with a curved foot portion I26 which bearsagainst the face of the mounting plate 41 so that when the lever ismoved to the left, as shown in Figure 6, the shaft I I9 and arm I I2will be moved in a similar direction, thus freeing the half nut fromengagement with the timer shaft. By means of a spring I21, mounted onthe timer rod'between a bearing. III and block member II I, the rod H9is normally maintained in a position such that the half nut is engagedwith the timer shaft. I

The timing mechanism, so far described, is employed for the purpose ofstopping the entire machine. To the end that the feeding mechanism andmeter unit may be separately arrested while the filter support shaftsand the brush carrying shafts are still being actuated an arm I28provided with a foot or shoe I29 is fixed to the timer rod to rotatetherewith. When the half nut is engaged with the timer shaft, it will beappreciated that the timer rod will be rotated on movement of the timernut.

Such rotation will, of course, cause the arcuate movement of the metercontrol, arm I28. It

should be noted that the movable coupling mem-- ber 8| on the shaft 88is provided with an enlarged end I88 which possesses the shape of atruncated cone. As the control arm I28 rotates the shoe thereof engagesthe conical end I88 of the coupling member 8| and moves it towards theleft on its shaftagainst a spring I8I, the latter being positionedbetween the end of the coupling member and a bearing 88. This movementof the coupling member causes it to be disengaged from the shaft 88 sothat rotation of the latter with.

resultant actuation of the meter unit is prevented.

For the purpose of best disclosing the movement of arms 2 and I28 wehave shown in Figure 8their positions at the opposite extremities oftheir respective paths of travel, their initial positions beingindicated by the dotted lines. Obviously, by suitable rotation of rodIIII which may be accomplished by operation of control lever I28 thecoupling member 8| is freed from its engagement with the control arm I28so that the spring |8I will force the coupling member to its normalposition of engagement with its cooperating coupling member 82 on shaft88.

In order to determine the time of impregnation, the timer rod H8 isprovided with a pointer I82, fixed thereto in any conventional manner,which passes across a scale on an arc I88 carried on th control mountingplate. The are I88 is so graduated that units of distance thereon, arecalibrated into units of time of impregnation. Thus in setting themachine for any desired time of impregnation, the lever I28 is swung tothe left and rotated until pointer I82 is opposite the desired point ofthe scale I88. After this the lever or handle I 28 is released so thatthe half nut engages the timing shaft. By this means a predetermineddegree of impregnation is obtained.

In the operation of our machine, the hopper 88 is charged with theimpregnating material to be employed. After this, the unimpregnatedfilters are mounted by being screwed into the threaded hollow support.shafts III of an impregnating compartment. One compartment of theimpregnating box having been so loaded, the cover therefor is moved overthe same so as to tightly close it. Control valve 88 is then opened soas to allow air under pressure to flow through the chamber 88 and intothe impregnating box. At the same time operation of the vacuum pumpconnecting with the hollow filter material support shafts is begun, thethree-way valve 61 having been first positioned so that the compartmentbeing employed for the treatment of the filter material is incommunication with the vacuum pump. As previously noted, the suctionexhaust through the manifolds connecting to the filter support shafts iscontrolled by means of the valve 68 which valve is set as desired. Also,actuation ofthe blower I2 connecting with the compartment in use iscommenced.

Having completed these operations and determined the degree ofimpregnation desired, the

is released, causing engagement of the half nut with the timer shaft.

In addition to these operations, belt shifting lever 8| is so moved thatbelt 81 is connected to the compartment mechanism drive wheelof thecompartment in use. The device is now ready for impregnation of thefilters and to this end switch button control'lever IN is operated in amanner to cause the finger 88 to depress the starter button on theswitch, which causes the actuation of the motor 8| and the parts of themachine which the motor drives.

As already noted, by means of the sprockets on the hollow filter supportshafts and on either the shaft I! or I8, the filters within thecompartment employed are rotated while oscillation of the brush carryingshafts occurs by reason of their linkage connection to the compartmentmechanism driveshaft. At the same time shafts 88 and 88 are rotatedwhich by reason of the belting and chains and sprockets employed, causesthe I rotation of the paddles 81 and th meter unit 5|,

allowing the latter to carry impregnating material into the chamber 88where it is blown from thegrooves in the meter through pipe 58 into theimpregnating compartment.

Rotation of the unimpregnated filters, it will be appreciated, allowsthe air current to contact with their entire surface thus insuringimpregnation of all-parts of the filters. At the same time dividedparticles of impregnating material into the pores of the filter materialundergoing treatment while the rotation of thefilter material insuresimpregnation of all the parts of the filter material undergoingtreatment. By use of the brushes I6, excess impregnating material on thefilters is removel and deposited in the bottom of the impregnatingcompartment from whence it is recovered .by means of the suction blowerI2 discharging through the exhaust line I8.

During the operation of the machine as described, the half nut I I6engaged with the timer shaft is being constantly moved outwardly, thatis in a direction towards the side of the machine disclosed in Figure 1.Because of its connection with the half nut and with the timer rod III),the half nut connecting arm II2 causes the rotation of the timer rodIII) as the half nut is moved along the timer shaft. This rotationeffects the movement of the meter controlarm I28 sothat its shoe I28 ismoving the coupling member 8| out of engagement with its cooperatingmember 82. When such disengagement is completely made, rotation of theshaft 88 and operation of the meter and feeding device ceases, thusdetermining the amount of impregnating 'material discharged into thechamber 88 in the along the shaft finally reaches such a position thatthe switch button is depressed motor 8| is stopped.

During'the impregnation taking place in the compartment being employed,the other compartment is undergoing loading in a manner like thatpreviously described. When the filters first being treated areimpregnated and operaso that the tions within that compartment ceased,the top 54 is moved so as to cover the compartment with the undertreatedfilter material therein. Operations for the actuation of the deviceswithin the compartment containing the untreated filter material of anature similar to those just described are then gone through, suchchanges as'are necessary being made in the positioning of the controlvalves and the compartment mechanism drive belt.

We have found that our machine works successfully when impregnatingporous filter material with any finely divided or pulverized substance.Preferably, because of the efiicient filters it produces, lamp black isemployed as the impregnating material. However, our invention is in noways limited to this particular impregnation substance, as theimpregnating compound or mixture employed will not effect thefunctioning and the efficiency of our machine.

While we have disclosed various forms'of driving means for thismechanism of our invention, it is to be understood that other anddifferent types of driving connections, including belts, chains, shafts,gears, clutches, couplings, or any combination of these may be employedwithout departing from the spirit of the invention or the scope of theappended claims. Likewise, it will be appreciated that the variousmechanisms may be driven by any nitable source of power and are notlimited to actuation by electric motors as shown.

In addition, it will be appreciated that 11 de-' sired, the speed ofrotation of the meter unit, timer shaft, and the rotating andoscillating mechanism within each compartment, may be varied as desired,through the use of gears or pulleys with different diameters. Forexample, by such practice the speed of the meter unit which will effectthe quantity of impregnating material introduced into the mixing chambermay be accelerated or decreased.

Although, we have shown a machine having an impregnating box providedwith only two compartments, it will be appreciated that any number ofimpregnating boxes may be placed on one machine bed. Through suitablestructural changes, an impregnating box containing three or morecompartments may be employed.

From the foregoing description it will be appreciated that we havedesigned a novel and efilcient machine for impregnating filter materialwith a finely divided or pulverized substance, such for example as lampblack. Moreover, a machine in which the entire surface of a filter maybe subjected to impregnation, as well as a device for insuring a uniformdegree of impregnation of a plurality of filters has been provided. Itshould also be noted that the machine described is of simple and easyoperation and may be continuously actuated so as to impregnate one of aplurality of sets of untreated filters.

While we have shown and described the preferred embodiment of ourinvention, we wish it to be understood that we do not confine ourselvesto the precise details of construction herein set forth byway ofillustration, as it is apparent that many changes and variations may bemade therein by those skilled in the art, with out departing from thespirit of the invention, or exceeding the scope of the appended claims.

We claim- 1. A filter impregnating machine comprising a frame, animpregnating box containing a compartment mounted therein, means insaid'oom-.

partment for rotatably mounting filters undergoing treatment, means forrotating said filters,

and means for introducing a gas containing finely divided particles ofimpregnating material into said compartment of said box.

2. A filter impregnating machine comprising a frame supporting animpregnating box containtaining finely divided particles of impregnatingmaterial-into the closed compartment.

3. A filter impregnating machine comprising a frame supporting animpregnating box containing a compartment, means for rotatably mountinga plurality of filters in said compartment, means for rotating thefilters in said compartment, means for introducing a gas containingfinely divided particles of impregnating material into the compartmentcontaining filters undergoing treatment, and means for brushin excessimpregnating material from the filters while undergoing treatment.

4. A machine for impregnating filters comprising a frame supporting animpregnating compartmentrmeans in said compartment for rotatablymounting a plurality of filters, means for closing a compartmentcontaining filters undergoing impregnation, means for introducing a gascontaining finely divided particles of impregnating material into theclosed compartment, and a brush mechanism associated with each filterfor removing excess impregnating material therefrom during impregnation.

5. A filter impregnating machine comprising a frame supporting acompartment having a plurality of hollow shafts rotatably mountedtherein, means for mounting a filter on each shaft, means connectingeach of said hollow shafts to a suction pump, means for rotating each ofsaid shafts, and means for introducing a gas containing finely dividedparticles of impregnating material into said compartment.

6. An impregnating machine comprising a frame supporting an impregnatingcompartment having a plurality of hollow shafts rotatably mountedtherein, means for supporting a filter from each of said shafts, meansfor closing said compartment containing filters being impregnated, meansfor introducing finely divided pare ticles of impregnating material intothe closed compartment while rotating the filters therein,

and means for exhausting the air from within the filters in the closedcompartment being rotated while undergoing treatment.

'7. A filter impregnating machine comprising a frame supporting acompartment having a plurality of hollow shafts rotatably mountedtherein, means for mounting a filter on each shaft, means connectingeach of said hollow shafts to a suction pump, means for rotating each ofsaid shafts, means for introducing a gas containing finely dividedparticles of impregnating material into said compartment and a brushmechanism for removing excess impregnating material from the surface ofthe filters undergoing impregnation.

8. An impregnating machine comprising a frame supporting an impregnatingcompartment having a plurality of hollow shafts rotatably mountedtherein, means for supporting a filter from each of said shafts, meansfor clos- 9. An impregnating machine comprising .a frame supporting an.impregnating compartment having a plurality of hollow shafts rotatablymounted therein, means for supporting a filter from each of said shafts,means for rotating each of'said shafts, means for introducing a gascarrying particles of impregnating material into sa d compartment,suction means for removing from said compartment excess impregnatingmaterial deposited therein and means for evacuating air from within thefilters undergoing impregnation associated with each hollow shaft.

10. A filter impregnating machine comprising a frame supporting acompartment, a plurality of hollow shafts rotatably mounted within saidcompartment, means for supporting a filter from each shaft, means forclosing the compartment containing filters being impregnated, means forintroducing a gas containing finely divided particles of impregnatingmaterial into the-closed compartment, means for rotating the filtersupport shafts in the closed compartment, other means associated witheach hollow filter support shaft for evacuating air from within thefilter supported thereon in the closed-compartment, and suction meansfor removing from the closed compartment excess impregnating materialdeposited therein.

11. An impregnating machine comprising a frame supporting animpregnating compartment having a plurality of hollow shafts rotatablymounted therein, means for supporting a filter from each of said shafts,means for rotating each of said shafts, means for introducing a gascarrying particles of impregnating material into said compartment, abrush mechanism associated with each filter support shaft for sweepingofi excess impregnating material on the surface of the filter supportedthereon, suction means for removing from each compartment excessimpregnating material deposited therein and means associated with eachhollow shaft for evacuating airfrom within the filters undergoingimpregnation.

12. A filter impregnating machine comprising means for rotating thefilter support shafts with their filters and for actuating the brushmechanism within the closed compartment, means communicating with thehollow shafts of the closed compartment for evacuating air from thefilters therein, and suction means for removing excess impregnatingmaterialdeposited within the closed compartment.

13. A filter impregnating machine comprising a frame, a plurality ofcompartments for holding filters for impregnation, a conduit connectingwith a gas under pressure, means communicating with said conduit forintroducing therein a predetermined amount of a finely dividedimpregnating material, and selective means forconnecting said conduitwith any compartment.

14. A filter impregnating machine comprising a frame, a compartment forholding filters under going impregnation, means associated-with saidcompartment for rotatively mounting said filters, a power source foractuating the same connected to said .rotative filter mounting means, aconduit connecting said compartment with a gas under pressure and meanscommunicating with said conduit for introducing therein a predeterminedamount of a finely divided impregnating material.

15. A filter impregnating machine comprising a frame, a compartment forholding filters undergoing impregnation, a closure for said compartment,a hopper for containing finely divided impregnating material mounted onsaid frame, said hopper being provided with a chamber at its lower endclosed off from the remainder of the hopper by a rotatively mountedmeter roller, said roller being provided with a plurality of v grooveson its surface, a conduit connecting said chamber with a gas underpressure, a second conduit connecting said chamber with said compartmentand means for revolving said meter a predetermined time at a fixedspeed.

16. A filter impregnating machine comprising a frame, a compartment forholding filters undergoing impregnation, means associatedwith saidcompartment for rotatively mounting said filters,

va power source for actuating the same connected to said rotative filtermounting means, a hopper for containing finely divided impregnatingmaterial mounted on said frame, said hopper being provided with achamber at its lower end, canduits connecting said chamber with a gassupply under pressure and with said compartment, a rotatively mountedmeter roller in said hopper for introducing impregnating material intosaid chamber, means affording a detachable driving connection betweensaid power source and'said roller, and means actuated by said powersource for breaking said driving connection after a predetermined timeof operation to arrest the actuation of said meter unit.

17. A filter impregnating machine comprising a frame, a compartment forholding filters undergoing impregnation, means associated with saidcompartment for rotatively mounting said filters, a power source foractuating the same connected to said rotative filter mounting means, ahopper for containing finely divided impregnating material mounted onsaid frame, said hopper being provided with a chamber at its lower end,conduits connecting said chamber with a gas supply under pressure andwith said compartment, a rotatively mounted meter in said hopper, saidmeter being driven by said power source through a detachable drivingconnectiontherewith, a timer shaft driven by said power source, meansactuated by said timer shaft for breaking the driving connection betweenthe power source and the meter after a predetermined time of operationand other means actuated by said timer shaft for arresting the operationof the power source.

18. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each shaft,means for introducing a gas under pressure carrying finely dividedparticles of impregnating material into said compartment, a power sourcefor rotating said filter support shafts, an electric switch mechanismfor controlling the actuation of said power source, means carried bysaid frame for operating said switch so as to start said power sourceand means driven by said power source for operating said switch so as toarrest the actuation of said power source.

19. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each shaft,means for introducing a gas under pressure carrying finely dividedparticles of impregnating material into said compartment, 2, powersource for rotating said filter support shafts, an electric switchmechanism for controlling the actuation of said power source, a timershaft provided with threads driven by said power source, a half nutengaging said shaft, said half nut being mounted for movement lengthwiseof said shaft, and means carried by said half nut for operating saidswitch so as to arrest the actuation of said power source.

20. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each shaft,means for introducing a gas under pressure carrying finely dividedparticles of impregnating material into said compartment, a power sourcefor rotating said filter support shafts, an electric switch mechanismfor controlling the actuation of said power source, a timer shaftprovided with threads driven by said power source, a half nut engagingsaid shaft, said half nut being mounted for movement lengthwise of saidshaft, movable means supporting said half nut for freeing it fromengagement with said timer shaft, and a finger on said half nut foroperating said switch to arrest the actuation of said power source;

21. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each shaft,means for introducing a gas under pressure carrying finely dividedparticles of impregnating material into said compartment, a power sourcefor rotating said filter support shafts, an electric switch mechanismfor controlling the actuation of said power source, a timer shaftprovided with threads driven by said-power source, a half nut engagingsaid shaft, said half nut being mounted for movement lengthwise of saidshaft, movable and rotatable means supporting said half nut for freeingit from the timer shaft and engaging it with the timer shaft at anypoint desired on the threaded portion thereof, and a finger on said halfnut for operating said switch so as to arrest the actuation of saidpower source.

22. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each shaft,means for introducing a gas under pressure carrying finely dividedparticles of impregnating material into said compartment, a power sourcefor rotating said filter support shafts, an electric switch mechanismfor controlling the actuation of said power source, a timer shaftprovided with threads driven by said power source, a half nut engagingsaid shaft,

said half nut being mounted for movement lengthwise of said shaft,movable and rotatable means supporting said half nut for freeing it fromthe timer shaft and engaging it with the timer shaft at any pointdesired on the threaded portion thereof, said rotatable and movablesupporting means for the half nut having other means associatedtherewith for determining the degree of rotation of said support, and afinger on said half nut for operating said switch to arrest theactuation of said power source.

23. A filter impregnating machine comprising a frame supporting animpregnating compartment, a plurality of shafts rotatively mountedwithin said compartment, means for supporting a filter on each of saidshafts, a hopper for containing impregnating material, said hopper beingprovided with a chamber and a rotatable meter for introducingimpregnating material into said chamber, conduits connecting saidchamber to a supply of gas under pressure and to said compartment, apower source for rotating said filter support shafts, a shaft driven bysaid power source coupled to said meter by a detachable coupling member,a threaded timer shaft also driven by said power source, a half nutnormally engaging said timer shaft, said half nut being mounted formovement lengthwise of said timer shaft, means connecting said half nutwith a timer control rod so as to rotate the latter, and means carriedon said timer control rod for freeing said coupling member to arrest theactuation of the meter after a predetermined time of operation.

24. A filter impregnating machine comprising a frame supporting animpregnating compartment for holding filters undergoing treatment, aplurality of shafts rotatively mounted within said compartment, meansfor supporting a filter on each of said shafts, a hopper for containingimpregnating material, said hopper being provided with a. chamber and arotatable meter for introducing impregnating material therein, conduitsconnecting said chamber to a supply of gas under pressure and to saidcompartment, a power source for rotating said filter support shafts, ashaft driven by said power source coupled to said meter by a detachablecoupling member, a threaded timer shaft also driven by said powersource, a half nut normally engaging said timer shaft, said half nutbeing mounted for movement lengthwise of said timer shaft and formovement away from said shaft, means connecting said half nut to amovable and rotatable timer control rod so as to rotate the latter,means on said timer control rod for freeing said coupling member toarrest the actuation of the meter mechanism, and means associated withthe timer rod for moving and independently rotating the same.

25. A filter impregnating machine comprising a frame supporting animpregnating compartment for holding filters undergoing treatment, aplurality of shafts rotatively mounted within said compartment, meansfor supporting a filter on each of said shafts, a hopper for containingimpregnating material provided with a chamber and a meter forintroducing impregnating material into said chamber, conduitsconnectingsaid chamber to a supply of gas under pressure,

and to said compartment, 2. power sourcefor rotating said filter supportshafts, a shaft driven by said power source coupled to said meter by adetachable coupling member, a threaded timer shaft also driven by saidpower source, a half nut normally said timer shaft, said nut being111011118! for movement lengthwise of said timer shaft and'for movementaway from said shaft, means connecting said half nut to a movable androtatable timer control rod so as tov cause said rod to rotate, means onsaid timer rod for freeing said coupling member to arrest the actuationof the meter, means associated with the timer rod for moving andindependently rotating thesame, and other means associated with saidtimer rod for determining the degree of rotation given thereto by saidindependent rotating means.

26. A filter impregnating machine comprising a frame supporting animpregnating compartment for holding filters undergoing treatment, aplurality of shafts rotatively mounted within said compartment,means-for supporting a filter on each of saidshafta-a hopper forcontaining impregnating material provided with a chamber and a meter forintroducing impregnating material into said chamber, conduits connectingsaid chamber to a supply of gas under pressure and to said compartment,a power source for rotating said filter support shafts and ashaft-coupled to said meter mechanism by a detachable coupling member, athreaded timer shaft also driven by said power source, an electricswitch mechanism for controlling the actuation of said power source, ahalf nut normally engaging said timer shaft, said half nut being mountedfor movement lengthwise of said timer shaft and for movement away fromsaid shaft, means connecting said half nut to a movable and rotatabletimer control 'rodsoastocausesaidrodtorotatameanson,

said timer control rod for freeing said coupling member toarrest theactuation of the meter,

means associated with the timer rod for moving and independentlyrotating the same, and a finger on said half nut for operating saidswitch so as to arrest the actuation of said power source.

27. A filter impregnating machine comprising I a frame supporting animpregnating compartment for holding filters undergoing treatment,

a plurality of shafts rotatively mounted within said compartment, meansfor supporting a filter -on each of said shafts, a hopper for containingimpregnating material being provided with a chamber and a meter forintroducing impregnating material into said chamber, conduits connectingsaid chamber to a supply of gas under pressure and to said compartment,a power source for rotating said filter support shafts and a shaftcoupled to said meter by a detachable coupling member, a threaded timershaft also driven by said power source, an electric switch mechanism forcontrolling the actuation of said power source,- a half nut normallyengaging said timer shaft, said half nut being mounted for movementlengthwise of said'timer shaft and for movement away from said shaft,means connecting said half nut to a movable and rotatable timer controlrod so as to cause the rotation of said rod, means on said timer controlrod for freeing said coupling member to arrest the actuation of themeter mechanism aftera predetermined time of operation, means associatedwith the timer rod for moving and independently rotating the same,.other means associated with said timer rod for determining the degree ofrotation given thereto by said independent rotating means, and a fingeron said half nut for operating said switch so as to arrest the actuationofsaid power source.

28. A filter impregnating machine comprising meat for filters undergoingtreatment, a plurality of shafts rotatably mounted in said compartmentfor supporting filters thereon, a: hopper for containing impregnatingmaterial provided with a meter mechanism for introducing impregnatingmaterial into a conduit leading into said compartment, a power source,an electric switch mechanism for controlling the actuation of said powersource, means connecting said power source to said filter supportshafts, other means connecting said power source to said metermechanlsm, and still other means driven by said power source forarresting the actuation of the meter mechanism after a predeterminedtime and subsequently' arresting the actuation of the power source.

29. A filter impregnating machine comprising a frame supporting animpregnating compartment for filters undergoing treatment, a pluralityof shafts rotatably mounted in said compartment for supporting filtersthereon, a second group of shafts each provided with a brush beingmounted within said compartment, a hopper for containing impregnatingmaterial provided with a meter mechanism for introducing impregnatingmaterial into a conduit leading into said compartment, a power source,an electric-switch mechanism for controlling the actuation of said powersource, means connecting said power source to said support shafts so asto. rotate the same and to said brush carrying shafts so as to oscillatethe same, other means connecting said power in each compartment, meansfor securing a filter to each shaft, means for closing a compartmentcontaining filters being impregnated from the remainder of the box, ahopper for impregnating material associated with said frame, a meter insaid hopper for introducing impre ting material into a conduit, meansfor placing said conduit into communication with either compartment, atpower source, means for connecting said so power source with the filtersupport shafts of either compartment, other means affording a detachableconnection between the power source and the meter mechanism and stillother means driven by said power source for breaking the drivingconnection between said power source and said meter mechanism.

31. A filter impregnating machine comprising a frame supporting animpregnatingbox containing a plurality of compartments, a plurality ofshafts for supporting filters rotatably mounted in each compartment,means for securing a filter to each shaft, means for closing acompartment containing filters from the remainder of the box, a hopperfor impregnating material associated with said frame, a meter mechanismin said hopper for introducing impregnating material into a conduit,means for placing said conduit into communication with eithercompartment, 9. power source, means for connecting said power sourcewith the filter support shafts ofa frame supporting an impregnatingccmpart- *driven by said power for breaking the u driving connectionbetween said power source and said meter mechanism after a predterminedtime of operation and for arresting the operation of said power sourcesubsequent to the breaking of said driving connection.

32. A filter impregnating machine comprising a frame supporting acompartment for containing filters undergoing impregnation, a pluralityof hollow shafts rotatably mounted within said compartment, means forsupporting a filter on each shaft, aconduit connecting said compartmentwith a hopper containing impregnating material, a meter mechanism withinsaid hopper for introducing impregnating material into said conduit, apower source, means connecting said power source with said filtersupport shafts, other means affording a detachable connection betweenthe power source and the meter mechanism, still other means driven bysaid power source for breaking the driving connection between said powersource and said meter mechanism and for subsequently arresting theoperation of said power source, and means communicating with each ofsaid hollow shafts for evacuating air from within the filters supportedthereon.

33. A filter impregnating machine comprising 'a frame supporting animpregnating compartment for containing filters, a plurality of filtersupport shafts rotatably mounted within said compartment, means forsupporting a filter on each shaft, a conduit connecting said compartmentwith a hopper containing impregnating material, a meter mechanismassociated .with said hopper for introducing impregnating material intosaid conduit, a power source associated with said frame, meansconnecting said power source with said filter support shafts forrotating the same, other means aflording a detachable driving connectionbetween said power source and said meter mechanism, still other meansdriven by said power source for breaking the connection between thepower source and the meter mechanism after a predetermined time ofoperation and for subsequently arresting the operation of the powersource, and means communicating of said compartment for removingtherefrom excess filter impregnating material therein.

34. A filter impregnating machine comprising a frame supporting acompartment containing filters undergoing impregnation, a plurality ofhollow filter support shafts rotatably mounted within said compartment,means for supporting a filter on each shaft, a conduit connecting saidcompartment. with a hopper containing impregnating material, a metermechanism within said hopper for introducing impregnating material intosaid conduit, a power source, means connecting said power source withsaid filter support shafts, other means aflording a detachableconnection between the power source and the meter mechanism, still othermeans driven by said power source for breaking the driving connectionbetween said power source and said meter mechanism and for subsequentlyarresting the operation of said power source, suction meanscommunicating with each of said hollow shafts,

a filter from each shaft, a plurality of shafts each carrying a brushmounted within said compartment, a hopper containing finely dividedimpregnating material, a-meter mechanism for introducing impregnatingmaterial into said compartment, a power source, means for causing saidpower source to respectively rotate and oscillate the filter supportshafts and the brush carrying shafts, other means affording adetachableconnection between said power source and 'said meter mechanism, stillother means driven by said power source for breaking the connectionbetween the power source and meter mechanism after a predetermined timeof operation and for subsequently arresting the operation of the powersource, suction means communicating with said hollow filter supportshafts for evacuating air from within the filters carried thereon, andmeans communicating with the interior of said compartment for removingthe excess filter material deposited therein.

36. A filter impregnating machine comprising a frame supporting acompartment for containing a plurality of filters undergoingimpregnation, an airtight cover for said compartment, said cover beingprovided with a distributing manifold communicating with saidcompartment by a plurality of openings and with a conduit connected to asupply of impregnating material.

37. A filter impregnating machine comprising a frame supporting acompartment for containing filters undergoing impregnation, a cover forsaid compartment affording an air tight fit with the walls thereof, saidcover having a hollow interior, the lower surface of said cover at itscenter being provided with a slot extending transversely thereof, theupper surface of said cover being provided with an opening on one sideof said slot, and a conduit communicating with said opening and with ahopper for impregnating ma- 38. A filter impregnating machine comprisinga frame supporting an impregnating box containing a plurality ofcompartments for containing filters undergoing impregnation, an airtightclosure for the compartments of said box provided by a cover slidablymounted between the walls of said box, said cover being of a widthsufilcient to close a compartment, a flexible conduit connecting saidcover with a hopper containing impregnating material, and a secondconduit connecting said hopper with a supply of gas under pressure.

39. A filter impregnating machine comprising a frame supporting animpregnating box having a plurality of compartments for containingfilters undergoing impregnation, an air tight closure for thecompartments of said box provided by a cover with a hollow interiorslidably mounted between the walls of said box, said cover being of awidth sufficient to close a compartment and being provided with a hollowinterior, the upper surfaces of the cover communicating through aconduit with a hopper containing impregnating material, a second conduitconnecting said hopper with a supply of gas under pressure and the lowersurface of said cover being provided with a transversely extending slotfor communicating with the interior of the impregnating box.

40. An impregnating machine comprising a frame supporting animpregnating box having a plurality of compartments for containingfilters undergoing treatment, an air tight closure for said compartmentsprovided by a cover slidably mounted between the walls of said box, saidcover being of a width suflicient to entirely close a compartment, thecover being provided with a hollow interior, the lower surface of saidcover being provided at its center with a transversely extending slot,the upper surface of said cover being provided with an opening on oneside of said slot, a flexible conduit communicating with said openingand a. hopper containing impregnating material, and a second conduitconnecting said hopper with a supply of gas under pressure.

41. In a machine having a plurality of mechanism driven by a powersource, means for arresting the operation of one of said mechanismsprior to that of the entire machine comprising a detachable driveconnection between said power source andsaid machine, a threaded timershaft driven by said power source, a half nut engaging said timer shaftand mounted for linear movement along the same, means for causing saidtimer shaft to rotate a timer control rod and means carried on said rodfor breaking the connection between said power source and saidmechanism.

42. In a machine having a plurality of mechanisms driven by a singlepower source, means for arresting the operation of one of saidmechanisms and then subsequently the operation of the entire machine,said means comprising a detachable driving connection between said powersource and said mechanism, a threaded timer shaft driven by said powersource, a half nut engaging said timer shaft and mounted for linearmovement along the same, means for connecting said half nut to a timercontrol shaft for rotating the latter on linear movement of the halfnut, means carried by said timer shaft for breaking the drivingconnection between said power source and said mechanism after apredetermined time of linear movement of said half nut, and a. fingercarried on said half nut for actuating an electric switch mechanismcontrolling the operation of the power source.

43. A filter impregnating machine comprising a frame, a compartment forholding filters undergoing impregnation, a plurality of filtersrotatively mounted in said compartment, means for impinging directlyagainst said filters finely divided particles of impregnating material,and automatic mechanism for stopping said means to thereby controlthe'degree of impregnation of the filters.

44. A filter impregnating machine comprising a frame, a compartment forholding filters undergoing impregnation, a plurality of filtersrotatively mounted in said compartment, means for rotating said filters,means for introducing finely divided particles of impregnating materialinto said compartment, a source of power for operating both said means,and automatic mechanism for arresting said source of power after apredetermined operation.

45. In a filter impregnating machine, means for supporting a filter andmeans for directly impinging against said filter air under pressurecontaining finely divided particles of impregnating material.

46. In a filter impregnating machine, means for rotating a filterundergoing impregnation, and means for directly impinging against saidrotating filter air under pressure containing finely divided particlesof impregnating material.

47. In a filter impregnating machine, means for rotating a filterundergoing impregnation, means for withdrawing air from the interior ofsaid filter, andmeans for directly impinging against said filter airunder pressure containing finely divided particles of impregnatingmaterial.

48. A filter impregnating machine comprising a frame, a filter holdingcompartment supported by said frame, means for supporting a filter insaid compartment, means for rotating said filter, means for supplyingfinely divided particles of impregnating material to said compartment,and automatic means for cutting off the supply of impregnating materialafter a predetermined degree of impregnation of said filter.

49. A filter impregnating machine comprising a frame, a filter holdingcompartment supported by said frame, means for rotatively supporting afilter in said compartment, means for rotating said filter, means forsupplying finely divided particles of impregnating material to saidcompartment, and automatic means for cutting off the supply ofimpregnating material after a predetermined degree of impregnation ofsaid filter.

50. A filter impregnating machine comprising an impregnating box havinga plurality of separate compartments, means for supporting filters forundergoing impregnation in each compartment, and selective means forintroducing finely divided impregnating material into any onecompartment.

FRANK B. HALE. FRANK A. LOGAN.

